Centrifugal bowl



March 13, 1934. G 1 STREZYNSKI 1,950,868

CENTRIFUGAL BOWL Filed June 25, 1951 Patented Mar. 13, 1934 UNITEDSTATES PATENT OFFICE 1,950,868 i CENTRIFUGAL Bowl. George J. Strezynski,Poughkeepsie, N. Y., as-

' signor to the De Laval Separator Company, New

York, N. Y., a. corporation of New Jersey Application'june 25, 1931,Serial No. 546,757

10 Claims.

My invention is an improvement in centrifugal separating bowls.

The objects of my -invention are: the reduction to a minimum of theemulsication that occurs when liquids from the stationary feeding tubestrike the rapidly revolving walls vof the receiving chamber of thebowl; more uniform distribution of liquid about the circle of the bowl;easier cleaning of the parts of the bowl; and increased pumping effectwith same discharge diameter.

Most modern centrifugal bowls have, projecting up in the center, a topclosed tube, called a nave, adapted to t around and rest on the top ofthe spindle that supports and drives the bowl. Surrounding the nave andspaced from it is another tubular member, called a tubular shaft, havingon the outside, ribs to guide and support the frusto-conical devices,technically called discs, which divide the liquid in the main part ofthe bowl into thin layers and, on the inside, twoor more ribs to catchand accelerate the liquid entering the bowl. Centrifugal bowls havingthis construction are disclosed in many issued patents, for example, inthe Lindgren Patent No.

It is common practice to make these tubular shafts of cast materialwhich, as the interior shape is such as to be impossible to machine, is

rough and difficult to keep clean. The usual three o`r four ribsviolently whip the entering liquid, causing emulsication, and then throwit out into the bowl trated streams, causing, between the discs, anumber of sectors of rapid flow between which are sectors of relativelyslow flow.

In order to properly centrifuge all of the liquid passing through thebowl it is necessary that the flow shall be slow enough to provideadequate time for the liquid moving at the maximum speed.

As'a result of this the liquid remains much longer than necessary in thesectors of slow flow and the capacity of the bowl is thus greatlyreduced.

The improvement embodying my invention effects a much more evendistribution of liquid around the bowl, with resultant increase of bowlcapacity, and emulsication is reduced to a minimum. In constructing myimproved bowl, I proceed, preferably, as follows:

The inside of the tubular shaft is bored smooth, preferably somewhattaper, with the larger end at the bottom. Within the shaft is placed aremovable squirrel cage with not less than six, and preferably fromeight to sixteen, either vertical or long-pitch helicoidal slots, eitherof which in three or four concenmay be defined as vertically extensive,and which may be radial in their transverse extension but are preferablytangential rearwardly with respect to the direction of rotation.. A feedtube with a side outlet should be provided. This squirrel 00 cage takesthe liquid from the central space in many thin ribbon-likevstreams, witha minimiun of whipping, and discharges it through correspending channelsunder the tubular shaft into the body of the bowl in so many streamsthat the high and low velocity sectors are comparatively narrow andtherefore of comparatively small difference in velocity. y When thesquirrel cage is removed, the inside of the tubular shaft is smooth andeasily cleaned, and every part of the squirrel cage itself, while out ofthe bowl, is easily accessible for cleaning.

In the accompanying drawing, which illustrates an embodiment of myinvention: Fig. 1 is a vertical section of a bowl and Fig. 2 is apartial 75 vhorizontal section on the line 2-2 of Fig. 1.

The bowl shell a has a hollow nave b extending upward from its bottom.Around the nave and inside the tubular shaft c is the squirrel cage dhaving slots e. The lower ends of the slots e communicate with passages,f under the petticoat c of the tubular shaft. On the outside of thetubular shaft are ribs g that guide and support a nest of discs h, onlya few of which are shown, and through which are distributing holes i.'i. is a feed tube with tangential side outlets.

In operation, liquid jetting from the side outlets of the tube i iscaught in the slots e of the squirrel cage, flows down them and throughthe passages F whence it escapes to the distributing holes i and fromthem to the inter-disc spaces where the separation takes place.

The sharp edges of the bars of the squirrel cage, with a minimum ofagitation, whipping and emulsication, smoothly shear off, from theentering stream of liquid, thin layers which are smoothly propelledoutward with great pumping effect.

When the squirrel cage is taper, a slight jar loosensit so that it canbe readily removed.

Having now fully described my invention, what I claim and desire toprotect by Letters Patent:

1. In a centrifugal bowl, the combination with a shell having a centralnave and a tubular shaft surrounding and spaced from said nave andhaving passages thereunder, of Aa squirrel cage-like member within saidshaft and between it and the nave, said member having therethrough amultiplicity of rearwardly extending tangential slots adapted to eachreceive a small part of the liquid fed inside said member and dischargeit to said passages. 2. In a centrifugal a shell and its nave, of atubular shaft having a smooth bore, and a removable member adapted toiit around said nave and inside said bore and having a multiplicity ofnarrow vertically extensive slots cut therethrough. i 3. In acentrifugal bowl, the combination with a shell and its nave, of atubular shaft having a smooth bore, and a removable member adapted toiit around said nave and inside said bore and having a multiplicity ofnarrow vertically extensive rearwardly tangential slots cuttherethrough. 4. In a centrifugal bowl, the combination with a shell andits nave, of a tubular shaft having a smooth bore, and removable tapermember adapted to fit` around said nave and inside said bore and havinga multiplicity of narrow vertically extensive slots cut therethrough.

5. In a centrifugal bowl, the combination with a shell and its nave,l,of a tubular shaft having a smooth bore, and a removable taper memberadapted to iit around said nave and inside said bore and having amultiplicity of narrowvertically extension rearwardly tangential slotscut therethrough.

6. In a centrifugal bowl, the combination with a shell having a centralnave and a tubular shaft surrounding and spaced from said nave, of asquirrel cage-like annular member within and contacting with the shaftand between it and the nave, said member having therein a multiplicityof vertically extensive slots which at the outside are closed by theinner wall of the tubular shaft and at the inside open into that part ofthe tubular shaft which said annular member encloses, the lower endportions of said slots communicating with the interior of the bowl.

7. In a centrifugal bowl, the combination with a shell having a centralnave and a tubular shaft surrounding and spaced from said nave, of asquirrel cage-like annular member within and contacting with the shaftand between it and the nave, said member having therein a multiplicityof vertically extensive slots which at the outside are closed by theinner wall of the tubular shaft and at the inside open into that'part ofthe bowl, the combination, withl tubular shaft which said annular memberencloses, the lower end portions of said slots communicating with theinterior of the bowl, said slots in their lateral direction of extensionextending tangentally rearward.

8. I n a centrifugal bowl, the combination with a shell having a centralnave and a tubular shaft surrounding and spaced from said nave andextending substantially above the nave, of an annular member within andcontacting with the shaft and whose lower end is confined between thenave and the shaft said member having therein vertically extensive slotswhich extend laterally completely through said member, the slots at theoutside being closed by the inner wall of the tubular shaft and at theinside being, at their lower ends, closed by the nave and, above theirlower ends, opening into the open central part of the tubular shaft, thelower portions of said slots communicating with the interior of thebowl.

9. In a centrifugal bowl, the combination with a shell having a centralnave and a tubular shaft surrounding and spaced from said nave andextending substantially above the nave, of an annular member within theshaft provided with a multiplicity of vertically extensive passages, the

lower part of said annular member extending between the feed tube andthe nave, said annular member extendingl above the nave and enclosingthe open central part of the tubular shaft, said passages communicatingat their lower ends with the interior of the bowl and closed throughoutthe greater part of their length at the outside and opening in the upperpart of their length at the inside into the open central part of thetubular shaft. i

l0. In a centrifugal bowl, the combination with a shell having a centralnave and a tubular shaft surrounding and spaced from said nave andhaving passages thereunder, of a removable squirrel cage-like memberextending within the shaft between the nave and shaft and substantiallyabove the nave and having formed therein a multiplicity of slots whoselengthwise direction of extension approximates parallelism with the axisof the shaft and which above the nave open laterally into the open spacewithin the tubular shaft enclosed by said member.

GEORGE J. STREZY'NSKI.

